1.4 The internet

Question 1

the internet

Answer 1

a WAN

huge network of computers linked by a combination of wired and wireless transmission media

a global collection of interconnected networks

Question 2

hosting

Answer 2

a host is a computer dedicated to a purpose accessed by users at remote locations over networks

web hosting companies rent space on their servers for websites

the hosting companies handle all the technical and security issues

Question 3

domain names

Answer 3

every computer using the inernet has a unique internet protocol (IP) address

enables other computers to know where to send any requested data such as web pages

Question 4

IP addresses

Answer 4

used on the internet the same way a MAC address is used on a LAN

either 32 bit (IPv4) or 128 bit (IPv6) numbers

Question 5

DNS

Answer 5

domain name service/server

IP addresses are represented as URLs so they are easier to remember (domain name)

when a user enters the domain name, the DNS translates it back into the IP address

Question 6

the cloud

Answer 6

remote servers that store data and programs that can be accessed through the internet

Question 7

advantage of hosting

Answer 7

servers on on 24/7 so the website is always available

multiple users can access the website at once

provides greater security

Question 8

resolving the domain name

Answer 8

when a browser requests access to a host using its domain name, the client computer contacts a DNS server

the DNS server contains a database of domain names that allows it to look up the domain name and return the IP address (resolving the domain name)

Question 9

steps to resolving the domain name

Answer 9

• user enters domain name
• client contacts DNS server
• if the domain name is not in the server’s database, it contacts another server
• the second server resolves the domain name and returns it to the first server
• the server returns the IP address to the client
• the client then contacts the host using the IP address

Question 10

a) Define what is meant by web hosting [2]

b) Give two advantages of using a web host [2]

Answer 10

a) a web host provides space for a website on a server so that it can be accessed by internet users
b) the user does not need the technical knowledge to set up a web server or ensure that it is secure from hackers

Question 11

Explain why domain names are used [2]

Answer 11

domain names are easier for humans to remember and use than IP addresses, which are either 32 or 128 bit numbers

Question 12

Describe the process that takes place when a user requests access to a host using its domain name [3]

Answer 12

when a browser requests access to a host using its domain name

• client computer sends a request to the server of the DNS to resolve it into the numerical IP address
• the DNS servers store datavases of these domain names
• if the one contacted cannot resolve the domain name, it sends a request to another
• the IP address is returned to the client computer that can then contact the host